The AL-4 achromatic lens as an imaging device. AL-4 is an achromatic lens with an optical power of 4 diopters. It consists of two lenses of different glass types glued together. Reduces chromatic aberrations in the frame. According to the factory manual, it is used for macro photography of small objects, reproductions of paintings and similar works. According to the passport the shooting scale is 1:4.27-1:2.55. The connecting thread is m52. To work, the lens must be screwed onto a lens with a 52mm filter thread. I think it is possible to use lenses with other front threads, but then you need to use step-up or step-down rings.. My lens is made in Ukraine at the Tochprilad factory in Kharkiv. I think I had this lens in my box for about 10 years. I remembered its existence but didn't see the point of using it in any way. Recently, however, I decided to make my own mind up about this product and took some test shots with it.. The Jupiter 37 lens was chosen as the main lens...